Mirror Knight leaked?

IGN just posted an article previewing some of E3's must-watch titles. In their blurb for Dark Souls 2, Marty Sliva mentions a demo from weeks ago that ended with a battle against a Mirror Knight. This is the first time I've heard this mentioned.

That's seriously all I've got... Has anyone else picked up any additional details about this?

_________________ Night gathers, and now my watch begins.I am the sword in the darkness, I am the watcher on the walls, I am the fire that burns against the cold, the light that brings the dawn, the horn that wakes the sleepers, the shield that guards the realm of men. I pledge my life and honor to the knight's watch for this night and all the nights to come.

i actually would love a doppelganger or a knight the same size as you for the tutorial boss, they way you described the mirror knight sounds bad to me but that's just me. also it reminds me too much of the crystal knight for some reason.

_________________ Night gathers, and now my watch begins.I am the sword in the darkness, I am the watcher on the walls, I am the fire that burns against the cold, the light that brings the dawn, the horn that wakes the sleepers, the shield that guards the realm of men. I pledge my life and honor to the knight's watch for this night and all the nights to come.

having the same equipment and spells would be enough to make the fight hard. however you could abuse the system by going into the fight un armed then rearming after you are duplicated. however like has been said, its likely not a doppleganger but a trapped knight breaking free/being released.